1. Field of the Invention
The present invention relates to a liquid crystal display apparatus and a mobile terminal which display letter or image information and particularly, to a liquid crystal display apparatus and a mobile terminal having a liquid crystal panel which does not easily get out of order by an external impact.
2. Description of the Background Art
Generally, Liquid Crystal Display (LCD) is a displaying apparatus installed in a mobile terminal, monitor and the like and liquid crystal which is a material between liquid and solid condition is injected between two sheets of glass substrates formed as electrodes to display letters or images by adding an electric field.
As shown in FIG. 1, such liquid crystal display apparatus is installed in folder-type mobile terminal 1 and the like to display adjust or use condition or letter or image information, etc.
Particularly, since a liquid crystal panel composing the liquid crystal display apparatus can not emit light by itself, a back light sheet is installed at the rear side and accordingly letter or image information displayed on the liquid crystal panel can be recognized more clearly by penetrating light emitted from the back light sheet.
The back light sheet mainly employs a direct method for directly illuminating the front surface of the liquid crystal panel using Electro luminescence (EL) or an edge method for illuminating the liquid crystal panel using light diffused by a light transmission board having light sources at one or two sides of the liquid crystal panel. Between the methods, the liquid crystal display apparatus having a back light sheet by the direct method is mainly used for miniature electric devices such as mobile terminals and the like.
FIG. 2 is an exploded perspective view showing a conventional liquid crystal display apparatus by the direct method.
With reference to FIG. 2, the liquid crystal display apparatus 10 positioned in a mobile terminal is inserted-installed in a frame 17 fixed in a case of the terminal and as shown in FIG. 1, it displays letter or image information through a viewing window.
Since such liquid crystal display apparatus 10 has a liquid crystal panel 11, a Flexible Printed circuit (FPC) 12 is connected to the liquid crystal panel 11 and a reflection board 13 for reflecting light incident from the liquid crystal panel 11 is adhered to the rear surface as a single body.
The back light sheet 15 formed as a flat board shape, for illuminating the liquid crystal panel 11 is positioned on the rear surface of the liquid crystal panel 11 where the reflection board 13 is attached. Here, the reflection board 13 penetrates the light emitted from the back light sheet 15 in the direction of the liquid crystal panel 11.
Here, the reflection board 13 and back light sheet 15 forming the rear surface of the liquid crystal panel 11 are mutually attached by a double-faced adhesive tape 20.
Therefore, the liquid crystal panel 11, reflection board 13 and back light sheet 15 form a liquid crystal panel assembly and the liquid crystal panel assembly is inserted-assembled in the frame 17.
Particularly, the double-faced adhesive tape 20 is formed in a square band shape not to interfere the light illuminated from the back light sheet 15 and maintain an adhesive force between the liquid crystal panel 11 and back light sheet 15 and is adhered to the circumferential portions 13P and 15P between the reflection board 13 and back light sheet 15 adhered to the liquid crystal panel 11 as a single body.
As shown in FIG. 3, the double-faced adhesive tape 20 is adhered to the inner surface 17A of the frame 17 in FIG. 2 having some portions 20A and 20B which are formed protruded further than the periphery of the back light sheet 15.
On the other hand, as shown in FIG. 2, a polarizing plate 19 for forwardly penetrating the light penetrated through the liquid crystal panel 11 at the front side of the liquid crystal panel 11.
However, since in the conventional liquid crystal display apparatus, the double-faced adhesive tape 20 is adhered to the circumferential surface of the liquid crystal panel 11 and back light sheet 15, the liquid crystal panel 11 is easily transformed or broken by external impacts.
Namely, as shown in FIG. 3, since all parts of the liquid crystal panel 11 are adhered and bound to the back light sheet 15 by the double-faced adhesive tape 20, when instantaneous impact is applied as in the case that the liquid crystal display apparatus falls and is collided with a bottom, the lower substrate 11B of the liquid crystal panel 11 is adhered to the back light sheet 15 as a single body by the reflection board 13 and fixed to the frame 17 as shown in FIG. 4. However, the upper substrate 11A performs relative movement minutely contrary to the lower substrate 11B by the falling impact and the upper substrate 11A and the lower substrate 11B are instantaneously cracked apart in the xe2x80x9cAxe2x80x9d and xe2x80x9cBxe2x80x9d directions.
When the upper substrate upper substrate 11A and the lower substrate 11B are instantaneously cracked apart, vacuum foams are formed from the liquid crystal 11C filled between the both substrates 11A and 11B to the space cracked apart and a bleeding phenomenon of an exploded dotted pattern regardless of the inputted display signal. In the excessive case, letter or image information can not be clearly displayed by the bleeding phenomenon.
Particularly, in case of using a mobile communication instrument such as a mobile terminal, the bleeding phenomenon is often occurred when the instrument falls. At this time, as shown in FIG. 5, by the impact, the corner parts are damaged by the bleeding phenomenon and letter or image information is not displayed clearly.
Here, FIG. 5A shows the initial stage of the bleeding phenomenon that spots are occurred on the liquid crystal panel 11 right after the mobile terminal 1 falls in case the liquid crystal display apparatus 10 is installed in the mobile terminal 1 and FIG. 5B shows the bleeding expansion phenomenon that the spot (BL) is gradually expanded after 24 hours after the falling.
Therefore, to solve the above problem, the present invention provides a liquid crystal display apparatus and a mobile terminal capable of improving durability of the liquid crystal panel minimizing spot generation even though impacts by a falling or temperature change or a certain wrenching load is applied, by installing double-faced adhesive tape only at the edge portions except corner parts of the liquid crystal panel and the back light sheet and composing the liquid crystal panel and the back light sheet to be mutually adhered.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a liquid crystal display apparatus including a liquid crystal panel having a polygonal flat shape, a back light sheet positioned on the rear surface of the liquid crystal panel, for illuminating the liquid crystal panel with light and an adhesion member for mutually adhering the liquid crystal panel and the back light sheet by forming adhesion force in at least one part among edges except corner parts between the liquid crystal panel and the back light sheet.
Also, a mobile terminal for achieving the above object includes a transmission and reception means positioned at one side of a case, an input adjusting means exposed to external portion of the case being adjusted by a user, a control means for outputting a driving signal according to an input signal of the input adjusting means at the same time when the signals are inputted and outputted, being connected to the transmission and reception means, a liquid crystal display driving means operated by the output signal of the control means, a liquid crystal panel positioned in the case so that it can be shown from the outside, for displaying letter or image information by the liquid crystal display driving means and an adhesion member installed at least one part among edges except corner parts at the flat portion of the liquid crystal panel for supporting the liquid crystal panel in the case.
The foregoing and other, features, aspects and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.